<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <script src="https://cdn.bootcdn.net/ajax/libs/vue/2.6.10/vue.js"></script>
</head>
<body>
<div id="app">
  <button @click="handler">修改基本数据</button>
  <p>{{msg}}</p>
</div>
<script>
  const vm = new Vue({
    el:"#app",
    data(){
      return{
        msg:"hello"
      }
    },
    methods:{
      handler(){
        // this.msg = "bye Vue"
        // Vue实例上的$data里面进行数据代理
        this.$data.msg = "bye Vue"
      }
    }
  })
</script>
</body>
</html>